Dishwasher



Feb. 27, 1968 c, LOPP ET AL 3,370,598

DISHWASHER I Filed Oct. 20, 1965 2 Sheets-Sheet l 0% E Z mllll Feb. 27, 1968 c. R. LOPP ET AL 3,370,598

DISHWASHER Filed Oct. 20, 1965 2 Sheets$heet 2 United States Patent Ofi" 3,370,598 DISHWASHER Charles R. Lopp, White Bear Lake, and Wilbur G. Peyer, St. Paul, Minn., assignors to Whirlpool Corporation, a corporation of Delaware Filed Oct. 20, 1965, Ser. No. 498,850 3 Claims. (Cl. 134111) ABSTRACT OF THE DISCLOSURE This invention relates to an article washing apparatus such as a dishwasher.

Automatic dishwashers in which dishes or other articles being Washed are placed in racks in -a tub and sprayed with detergent solution and with rinse water have become quite common.

One feature of the invention is to provide an improved automatic dishwasher comprising means for circulating liquid in a tub over articles held in a holder therein, means for separating solids from the liquid during circulation thereof over the holder, means for grinding these solids to finer particle sizes, means for draining liquid from the tub and means for operating the grinding means during the draining.

Other features and advantages of the invention will be apparent from the following description of one embodiment thereof taken in conjunction with the accompanying drawings. Of the drawings:

FIGURE 1 is a fragmentary vertical sectional view through a combined dishwasher and solids grinder embodying the invention.

FIGURE 2 is a fragmentary vertical sectional view similar to the lower portion of FIGURE 1 but with the parts separated in an exploded view for clarity of illustration.

The dishwasher disclosed in the accompanying drawings comprises a tub 11 having a top 12 that is provided with a raised peak 13 at approximately its center. The bottom of the tub 11 is provided with a sump 14 also at approximately the center.

Beneath the tub 11 the apparatus is provided with an electric motor 15 having a shaft 16 rotatable in a bearing 17. The upper part of the vertical shaft 16 above the bearing 17 is attached to a drive sleeve 18 by a transverse pin 19.

The drive sleeve 18 has attached. thereto an impeller 20 for providing a drain pump. Surrounding this impeller 20 is a generally cylindrical shredder ring 21 of the usual type for grinding solids materials thrown thereagainst by the rotating impeller 20. Thus, the impeller and shredder ring operate as the usual garbage disposer in grinding relatively large solid pieces into smaller particles which are flushed to the sewer with the drain water.

The bottom of the drain impeller is recessed and contains therein a seal assembly 22 and 22a that is located around the drive sleeve 18.

Immediately above the shredder ring 21 that surrounds the drain pump impeller 20 is a drain filter 23 having an open center 24. Above this drain filter 23 is an inlet dif- 3,3?fi,598 Patented Feb. 27, 1968 fuser 25 having radial vanes 26 integral with a bottom outwardly flaring skirt 27 provided with spaced inlet openings 28. The inlet diffuser, as stated, is positioned above the drain impeller and beneath a pump impeller 29. The pump impeller, as is shown in FIGURE 2, is provided with spaced splines 30 that are normally in driving engagement with similar splines 31 on the drain impeller 20. As is also shown in FIGURE 2, the drive sleeve 18 and the bottom of the drain impeller 20 also have splined connections.

The pump impeller 29 is mounted on an impeller shaft 32 which as is shown in FIGURE 2 is attached to the top of the drain impeller 20 by means of a threaded lower post 33 on the impeller shaft and is sealed thereto by an O-ring 34.

The hub 35 of the impeller 29 that surrounds the shaft 32 is used to mount the lower spray arm 36 which includes the usual pair of laterally extending arms 37 and a hollow hub 38.

The hollow hub 38, as is shown most clearly in FIG- URE 2, has a top mounting part 39 with spaced liquid flow openings 40 therearound with this top part serving to mount the unit on the upper end 41 of the impeller shaft 32. The spray arm assembly of arms 37 and hub 38 is thus suspended from the top end 41 of the impeller shaft and the spray arm assembly 36 is rotatable about a bearing 42 on this upper end 41 by the usual reactive force of the outwardly sprayed liquid as indicated by the arrows 43. The assembly is locked in position on this upper end 41 of the shaft 32 by a retaining ring 44 attached to the upper end of this shaft. Between the retaining ring 44 and the upper end of the mounting part 39 there is provided a thrust washer 45.

The lower end of the hub 38 is provided with an outwardly flaring skirt portion 46 surrounding the pump impeller 29 and extending therebelow. The skirt 46 is located immediately above the inlet diifuser vanes 26.

As previously mentioned, the retaining ring 44 and thrust washer are located on the upper end 41 of the impeller shaft 32. The portion of this shaft 32 between the hub 35 and the top mounting part 39 is also provided with a retaining ring 47 and a thrust Washer 48.

The drain impeller 20 is surrounded by a lower pump casing 49 having an upwardly and outwardly flared flange 50 that is fastened to the bottom of the sump 14 to span an opening 51 therein and thus form a part of the bottom of the sump. This flange 5i and thus the lower pump casing is held in position by a series of circularly arranged screws 52 engaging the flange 50 in the adjacent annular part of the bottom of the casing 11. As can be seen in FIGURE 1, this arrangement provides that the lower part of the unit which includes a drain tube 53 is beneath the tub 11 but above the motor 15.

The outwardly and upwardly flared flange 50 on the lower pump casing 49 provides an annular opening to the inlet diffuser 25 and thus upwardly to the pump chamber containing the pump impeller 29 and defined by the depending skirt portion 46 of the spray arm assembly 36. The spaced vanes 26 provide for even flow of liquid into the pump impeller 29. Because the openings 28 in the skirt 27 of the diffuser 25 provide downward access to the drain impeller 24 the annular inlet openings 54 to the pump casing 49 provide for flow both upwardly into the pump impeller 29 and downwardly into the drain impeller 20. As can be seen from FIGURE 1, the two impellers are vertically aligned with the pump impeller being above the drain impeller.

Surrounding the bottom of the inlet diffuser 25 in the region of the lower part of the vanes 26 is a recirculation filter 55. This filter has a flexible rubber top 56 surrounding the depending skirt portion 46 of the spray arm assem- 3 bly 36 and a screen bottom 57 that extends across the inlet defined by the edges of vanes 26 to the inlet diffuser 25.

The inlet diffuser 25 is provided with an annular mounting flange 58 that is attached to the upper surface of the lower pump casing 49 as by a plurality of attaching screws 59.

The motor is of the type that can be rotated in either of two directions. When rotated in one direction the recirculation pump impeller 29 recirculates liquid in the tub 12 in the manner to be described hereinafter. When rotated in the opposite direction the drain impeller pumps liquid from the tub 11 through the drain tube 53.

Mounted above the lower spray arm assembly 36 is a generally cylindrical flow nozzle 69 having a vertical central passage 61. An annular center tube retainer 63 is attached to the bottom of a vertical tube 64 by means of a set screw 65. This tube at an intermediate area thereon has an outwardly extending annular flange 66 which bears against a top bearing 67 around the tube 64. A bottom bearing 68 similar to the top bearing 67 is held in position against the top of the center tube retainer 63. These bearings 67 and 68 and thus the tube 64 are held in place by an upwardly extending wire framework 69 mounted on the bottom dish rack 69a. Extending between a bottom connector flange 62 and the center tube retainer 63 is an expendable and contractible bellows connector 70 preferably made of a flexible plastic material. The top of the connector 70 is held in position on the bottom of the tube 64 by means of a clamp ring 71. The bottom of the connector 70 is held in position by frictional contact with the connector fiange, 62. Positioned in e the lower end of the center tube 64 is a flow straightener 72 that is provided with vertical internal vanes 73. The flow straightener is intended to convert the rotational components of fiow entering the bottom of the tube 64 to approximately axial flow.

Mounted on the upper end of the center tube 64 as by screws 74 is a top spray arm 75 also designed to be rotated in the customary manner by the reactive force of liquid jets issuing from the spray arm 75 in the normal manner at an angle as indicated by the arrows 76. The liquid spray is thereby projected toward and over articles such as dishes (not shown) held in a customary upper dish rack 77 similar in its function to the bottom rack 69a.

Centrally of the upper spray arm 75 and aligned with the vertical tube 64 is a nozzle 78 having an outlet opening 79 at the top thereof for projecting a jet of liquid (not shown) toward the tub top 12.

Mounted on this top 12 at the raised peak 13 thereof which is directly above the nozzle opening 79 is a rotatably mounted spray device or spinner 80. This receiver is rotatably mounted about a vertical axle 81 and is of generally inverted cup-shape with a flat bottom 82 and a generally cylindrical rim 83 in the form of spaced vertical vanes. The spray device 80 is provided with an upwardly and outwardly sloped false bottom 84 which slopes from the axle 81 toward the rim 83. The axle 81 is located vertically approximately directly above the nozzle opening 79.

The apparatus of this invention when used to wash dishes or similar articles operates in the following manner. The liquid, whether detergent solution or rinse water, gathers in the sump 14 at the entrance 54 to the pump impeller 29. During the washing portion of the machine cycle the motor 15 rotates the shaft 16 in a direction such that the recirculating pump '29 draws the liquid from sump 14 through filter 55 and forces a portion of it out the hub 38 into the lower spray arms 37. The reaction of the sprays 43 causes the spray arm assembly 36 to rotate and spray dishes and other articles in the lower rank 69a. The recirculation pump 29 forces another portion of the liquid up through the liquid flow openings 40 above the impeller 29 and through the flow nozzle passage 61 and the bellows connector 70 into the tube 64. From the upper end of the tube 64 this portion of the liquid then has one part flowing outwardly through the top spray arm to spray the bottoms of dishes and other articles in the rack 77 and another portion flowing vertically in a jet out the nozzle opening 79 to the spray device or spinner 80. This jet strikes the spinner at about the center axle 81 and the liquid force is diverted by the inverted cup-shaped bottom 84 toward the annular rim spaced vanes 83. The liquid issuing between vanes 83 causes the spray device to spin about its axle 81 and spray the tops of articles within the rack 77 and spray the inner surface of the tub top 12 to prevent the accumulation of soil thereon.

During this washing operation of the apparatus large solid particels are gathered on the bottom 57 of the filter screen 55 that is beneath the recirculation impeller 29. Because the rotation of the motor shaft 16 in the direction for washing, as previously described, has the effect of rotating the drain impeller 20 in an opposite direction from its normal pumping direction of rotation, the drain impeller blocks passage 'of the liquid from the sump 14 into the drain from tube 53. Furthermore, this reverse rotation of the drain impeller 20 aids in depositing the large solids on the bottom 57 of filter screen 55.

During the drain and garbage grinding operation the direction of rotation of the motor shaft 16 is reversed by reversing the direction of motor 15. This causes the recirculation impeller 29 to rotate in an opposite from normal direction with the result that liquid from the impeller 29 is pumped downwardly to backwash the screen 55 and force the solids through the central opening 24 in the drain filter 23. After being forced past the drain filter 23 the liquid is pumped out the drain tube 53 to the sewer or other place of disposal and at the same time the drain impeller 20 shreds the large pieces of solids to fine particles against the shredder ring 21.

The drain filter 23 is used to block the passage of solids within t-heconfines of the shredder ring 21 from being drawn back into the recirculation impeller 29 and thus the liquid recirculated thereby during rotation of the impeller 29 in its normal direction.

Because rotation of the motor shaft 16 in the direction for washing, as previously described, has the effect of rotating the drain impeller 20 in an opposite direction from its norm-a1 pumping direction of rotation, the drain impeller sets up a vortex liquid flow path from inlet open ings 28 downwardly through open center 24 of drain filter 23 and upwardly through filter 23 to pump impeller 2 9. Since the openings of filter 23 are substantially smaller than those of filter 55, filter 23 removes the small food and dirt particles from the liquid flowing therethrough.

A liquid flow path is simultaneously set up from impeller 20 through openings 21A in shredder ring 21 to inlet 53A of drain tube 53. A vortex flow results at inlet 53A, in drain tube 53 and in hose 53B, as liquid is centrifugally ejected from pump casing ramp 49A. The small particles in the liquid flowing to tube 53 and hose 53B separate from the liquid and are deposited in hose 5313. As the liquid loses its velocity, 'it is returned to pump impeller 20 through the low pressure area in the center of the vortex. Furthermore, the upward flow of liquid from drain impeller 20 aids in depositing the large solids on the filter screen 57.

At the completion of the washing operation, the apparatus goes through a drain operation in which the liquid is drained from the tub and the large solids collected on the filter screen 57 and the small particles collected on filter screen 23 are directed to impeller 20 to be ground up as in an ordinary garbage disposer for passage into the sewer with the liquid. During this drain and garbage grinding portion of the machine cycle the apparatus operates as follows.

In the apparatus of this invention the recirculation pump 29 and the drain pump 20 and associated parts can be assembled as a package unit and installed in the tub 11 as a unit. These parts include all the elements from the motor up to and including the retaining ring 47. As mentioned previously, the drain filter 23 provides a means for trapping and holding small solids during the wash operation in order to decrease the redeposit of these small particles on the articles being washed. During the pump-out operation in which the solids are ground to fine particles by the drain impeller and the shredder ring 21, any solids gathered on the filter 23 will be flushed therefrom. The result is that the filter is automatically cleaned during each pump-out and garbage grinding operation.

In the illustrated apparatus all of the parts from the connector flange 62 through the top spray arm 75 may be subassembled as a unit and mounted on the lower dish rack 69a. The connector flange 62 and the bellows connector 70 function to provide a flat, non-jamming contact seal surface between the bottom of the connector flange 62 and the top of the flow nozzle 60. The bellows connector 70 being made of flexible material provides flexible compression contact between the flange 62 and the top of the flow nozzle. This seal is provided by the lower spray arm assembly 36 rising to meet the connector flange 62 when subjected to internal water pressure in the lower spray arm assembly.

The pump casing 49 also serves as the end bell for the motor 15 being held in place thereon by spaced bolts 85. The force of the drive sleeve 13 contacts the face of the motor bearing as shown at the bottom of FIGURE 1 so as to provide a thrust bearing structure for this assembly.

Having described our invention as related to the embodiment shown in the accompanying drawings, it is our intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

The embodiment of the invention in which an exclusive property or privilege is claimed is defined as follows:

1. Article washing apparatus, comprising: a tub; an

article holder; rotatable pump means for circulating liquid in said tub over said article holder; means for draining liquid from said tub; a rotatable drain pump normally rotated in one direction during said draining and in a reverse direction during said circulating, said reverse direction rotation of the drain pump during said circulating tending to flow liquid inwardly to one portion of said drain pump and outwardly away from another portion of said drain pump in a vortex path; particle separating filter means in said vortex path for separating particles from said liquid during said reverse rotation; grinding means in said drain means on the side of said filter means opposite said circulating pump for grinding and reducing solids during said draining; and means for simultaneously operating said grinding means and said drain pump.

2. The apparatus of claim 1 wherein said one portion of said drain pump is adjacent the pump center and said other portion is adjacent the pump periphery, and said particle separating means is annular and is also adjacent said periphery.

3. The apparatus of claim 1 wherein said means for circulating liquid comprises a first pump means having a first inlet, said means for draining liquid comprises a second pump means having a second inlet, and said filter means is located between said first and second inlets to be contacted by liquid in both said first and second paths.

References Cited UNITED STATES PATENTS 2,894,631 7/1959 Levit et al 134111 X 3,080,874 3/1963 Brucken 134115 3,084,701 4/1963 Hardy et al 134-115 3,129,711 4/1964 Schmitt-Matzen 134-115 X 3,217,884 11/1965 Long 134111 X 3,310,243 3/1967 Duncan et al 134115 X CHARLES A. WILLMUTH, Primary Examiner. R. L. BLEUTGE, Examiner. 

